I've read and enjoyed the works of Harlan Ellison for about thirty years. Ellison is a polarizing figure whose friends are legion and enemies, nearly so. I've had the honor and privilege of facilitating several appearances by Ellison in Arizona where he engaged, entertained, and enlightened audiences for hours on end. To learn more about those presentations go here and look for "Harlan at Glendale Community College, March 1999" and "Pictures from the Arizona University West Appearance."
You can get a sense of Ellison's charisma when you hear him perform readings of his own work and the work of others. Several audio recordings of Ellison have been available through Audible.Com and at bookstores such as Amazon.Com and Barnes and Noble.
I found an extensive list of Ellison recordings at the Islets of Langerhans. and there are some video clips of Ellison at Dark Carnival, but the most exciting news is concerning the documentary, Dreams with Sharp Teeth being shown April 19th in conjunction with an appearance by Harlan Ellison at the Writers Guild of America, more information can be found here with tickets available here. Clips of the documentary can be found here. Sweet dreams.